Using BEopt to Optimize Home Energy Performance

The story of BEopt starts in October 2000, when a seminal two-day workshop was held at the National Renewable Energy Laboratory (NREL) to explore the then-novel concept of zero net energy (ZNE) buildings. Representatives from the home-building industry, solar-thermal and PV manufacturers, consultants, national labs, and U.S. Department of Energy (DOE) came together to discuss what would be necessary for the broad adoption of ZNE buildings. One conclusion was that we needed a tool to determine the most cost-effective combination of technologies for ZNE homes. In other words, we needed to figure out how much efficiency to bundle with solar. More than a decade later, the economics have changed: Solar PV costs half what it did then. But the question remains the same and can be heard echoing in discussions about “how much insulation is too much?”